Fair value of financial instruments and marketable securities (Details) (USD $)
In Thousands, unless otherwise specified |
Mar. 31, 2014
|
Dec. 31, 2013
|
---|---|---|
Financial assets and liabilities measured at fair value on recurring basis | ||
Marketable securities | $ 130,730 | $ 127,053 |
Recurring basis | Total
|
||
Financial assets and liabilities measured at fair value on recurring basis | ||
Marketable securities | 130,730 | 127,053 |
Warrant liability | 113 | 58 |
Recurring basis | Significant other observable inputs (level 2)
|
||
Financial assets and liabilities measured at fair value on recurring basis | ||
Marketable securities | 130,730 | 127,053 |
Recurring basis | Significant unobservable inputs (level 3)
|
||
Financial assets and liabilities measured at fair value on recurring basis | ||
Warrant liability | $ 113 | $ 58 |